Polishing fixture

ABSTRACT

An end face polishing apparatus with improved polishing precision regardless of the length of ferrules when end faces of the ferrules are polished is provided. In an end face polishing apparatus polishing a rod-shaped member mounted at a polishing fixture by pressing the rod-shaped member against a lapping member on a lapping machine provided on a surface plate that is supported at the main body of the apparatus to rotate and rock, there are a plurality of rod-shaped guide members provided at the polishing fixture radially outwardly projecting and a tubular member capable of supporting the polishing fixture through the guide members on the surface plate. In this way, the guide members at the polishing fixture and the tubular member abut against each other so that the movement of the polishing fixture in the pressing direction is restricted.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a division of U.S. application Ser. No.10/187,574, filed on Jul. 2, 2002, now U.S. Pat. No. 6,736,551, andpriority thereto for common subject matter is hereby claimed.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an end face polishing apparatus forpolishing an end face of a rod-shaped member such as a fiber for opticalcommunication.

2. Description of the Background Art

Fibers for optical communication are adhesively secured in the centralhole of a ferrule, a main member of a connector, and then the ferruleend face and the end face of fibers are polished together and thusfinished in to a smooth, mirror surface. If the polished end faces ofthe ferrule and the fibers are not vertical to the central axis of theferrule or if there is a flaw on the polished faces, the precision inpositioning such ferrules as they are connected facing each other in anoptical connector is lowered, and the loss increases. Therefore, theface of the ferrule including the optical fibers must be polished withhigh precision.

A conventional apparatus for polishing the end faces of optical fibersis disclosed for example by Japanese Patent Laid-Open No. 26456/1991.The disclosed end face polishing apparatus includes an eccentric adapterthat rotates on a circle concentric with a rotating disc, and aplanetary gear that transmits the rotation of a revolving motor to theeccentric adapter. These elements are coupled in a lapping machine, sothat the lapping machine is allowed to rotate and revolve, while the endfaces of a plurality of ferrules held by a polishing fixture are pressedagainst a lapping member secured to the lapping machine for lapping.

As described above, in the conventional optical fiber end face polishingapparatus, the plurality of ferrules held by the polishing fixture arepressed by a spring or the like against the lapping member secured tothe lapping machine that rotates and revolves. However, the ferrules arepolished based on time, and the polishing length for the ferrules cannotbe controlled. When the ferrules mounted on the polishing fixture havethe same length, there would be no problems. However their lengths arenot equal because of the precision of ferrules or adhesive used tosecure optical fibers coming out from the tip ends of ferrules andcured. When therefore such ferrules having different lengths are slidinto contact with the lapping machine, the polishing fixture could beinclined relative to the lapping machine, and the lapping angle, theradius of curvature and the eccentricity could be deviated. The ferrulesafter the polishing could have different lengths.

SUMMARY OF THE INVENTION

The present invention overcomes the disadvantages of the conventionalart and it is an object of the invention to provide an end facepolishing apparatus with improved polishing precision regardless of thelength of ferrules when end faces of the ferrules are polished.

According to a first aspect of the present invention directed to asolution to the above disadvantages, an end face polishing apparatuspolishing a rod-shaped member mounted at a polishing fixture by pressingthe rod-shaped member against a lapping member on a lapping machineprovided on a surface plate which is supported at the main body of theapparatus to rotate and rock includes a plurality of rod-shaped guidemembers provided at the polishing fixture and radially outwardlyprojecting, and a tubular member capable of supporting the polishingfixture through the guide members on the surface plate. The guidemembers at the polishing fixture and the tubular member abut againsteach other, so that the movement of the polishing fixture in thepressing direction is restricted.

According to a second aspect of the invention, in the end face polishingapparatus according to the first aspect, the polishing fixture isprovided with at least three such guide members.

According to a third aspect of the invention, in the end face polishingapparatus according to the second aspect, the polishing fixture isprovided with six such guide members.

According to a fourth aspect of the invention, in the end face polishingapparatus according to any one of the first to third aspects, thetubular member is placed on the surface plate as its movement in theradial and circumferential directions is restricted.

According to a fifth aspect of the invention, in the end face polishingapparatus according to the fourth aspect, the tubular member and thesurface plate are closely contacted by magnetic force.

According to a sixth aspect of the invention, in the end face polishingapparatus according to any one of the first to fifth aspects, therod-shaped member is a ferrule including a ferrule tubular body forholding optical fibers and a collar member provided at a rear end of theferrule tubular body for holding coated optical fibers.

According to a seventh aspect of the invention, in the end facepolishing apparatus according to any one of the first to six aspects,the position to provide the lapping machine at the surface plate and theposition to provide the tubular member are level and controlled inheight by grinding, and the heights of the lapping machine and thetubular member are controlled by grinding.

According to an eighth aspect of the invention, an end face polishingapparatus polishes a rod-shaped member mounted at a polishing fixture bypressing the rod-shaped member against a lapping member on a lappingmachine provided on a surface plate that is supported at the main bodyof the apparatus to rotate and rock, the polishing fixture has aplurality of rod-shaped guide members radially outwardly projecting, andthe apparatus includes a tubular member supporting the polishing fixturethrough the guide members on the surface plate.

According to a ninth aspect of the invention, the surface of the guidemember in abutment against the tubular member in the end face polishingapparatus according to the eighth aspect is a plane.

According to a tenth aspect of the invention, the surface of the tubularmember in abutment against the guide member in the end face polishingapparatus according to the eighth aspect is a plane.

According to an eleventh aspect of the invention, the plane in the endface polishing apparatus according to the eighth aspect is horizontal.

According to a twelfth aspect of the invention, an end face polishingapparatus includes a tubular member at the outer periphery of a surfaceof a surface plate, and a lapping machine provided on the surface of thesurface plate, and the lapping machine is parted from the tubular memberin the axial direction and has a height lower than that of the tubularmember.

According to a thirteenth aspect of the invention, an end face polishingapparatus includes a tubular member at the outer periphery of a surfaceof a surface plate, a lapping machine that is provided on the surface ofthe surface plate, parted from the tubular member in the axial directionand has a height lower than that of the tubular member, and a polishingfixture having a guide member held slidably at a surface on the side ofthe tubular member opposite to the side facing the surface plate.

According to a fourteenth aspect of the invention, an end face polishingapparatus includes a tubular member at the outer periphery of a surfaceof a surface plate, a lapping machine that is provided on the surface ofthe surface plate, parted from the tubular member in the axial directionand has a height lower than that of the tubular member, and a polishingfixture having a guide member thereon. The guide member is held slidablyat a surface on the side of the tubular member opposite to the sidefacing the surface plate.

According to a fifteenth aspect of the invention, an end face polishingapparatus includes a tubular member at the outer periphery of a surfaceof a surface plate, and a lapping machine parted from the tubular memberin the axial direction and having a height lower than that of thetubular member on the surface of the surface plate, and the polishingheight is controlled based on the difference between the heights of thetubular member and the lapping machine.

According to a sixteenth aspect of the invention, an end face polishingjig includes a plurality of guide members radially outwardly projecting.

According to a seventeenth aspect of the invention, a polishing fixtureholds a ferrule at an inclined surface on a outer peripheral sidethereof, the ferrule includes a ferrule tubular body for holding opticalfibers and a collar member provided at the rear end of the ferruletubular body for holding coated optical fibers, the polishing fixtureholds the ferrule so that the front end of the ferrule tubular body ispositioned at the lower side and the lower part of the circle of thecollar member in contact with the outer periphery of the ferrule ispositioned at the upper surface.

According to an eighteenth aspect of the invention, an end facepolishing jig includes a guide member radially outwardly projecting atthe upper surface of the polishing fixture in the seventeenth aspect,and having a lower surface in a position on an extension of the uppersurface of the polishing fixture.

According to the invention, a polishing fixture is provided with a guidemember and a tubular member capable of supporting the polishing fixturethrough the guide member on a surface plate, so that the polishingfixture can be kept parallel to the surface plate, and the polishingprecision for bar-shaped members can be improved. In addition, thelengths of the bar-shaped members after polishing can be equalized.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic sectional view of an end face polishing apparatusaccording to one embodiment of the present invention;

FIG. 2 is a perspective view of a surface plate, a lapping machine and apolishing fixture according to the embodiment;

FIG. 3 is a plan view of the surface plate, the lapping machine and thepolishing fixture according to the embodiment;

FIG. 4 is a sectional view of the surface plate, the lapping machine andthe polishing fixture according to the embodiment;

FIG. 5A is a perspective view of the surface plate, the lapping machineand a tubular member according to the embodiment;

FIG. 5B is a plan view of the tubular member;

FIGS. 6A and 6B are plan views each showing a rod-shaped memberaccording to the embodiment; and

FIG. 7 is a sectional view showing how the rod-shaped member is securedaccording to the embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will now be described inconjunction with the accompanying drawings.

FIG. 1 is a schematic sectional view of an end face polishing apparatusaccording to one embodiment of the invention.

FIG. 2 is a perspective view of a surface plate, a polishing fixture,and a lapping machine. FIG. 3 is a plan view of the surface plate andthe polishing fixture. FIG. 4 is a sectional view of the surface plate,the lapping machine, and the polishing fixture.

As shown in FIG. 1, the central part of a first rotation transmissionplate 12 is rigidly coupled to the rotation shaft of a rotating motor11. A plurality of first coupling pins 13 are secured to the firstrotation transmission plate 12 concentrically around the rotation centerof the first rotation transmission plate 12. The first coupling pins 13are each rotatably coupled to an eccentric part of a corresponding oneof rotation transmission plates 14. Second coupling pins 15 are eachsecured at an eccentric part of a corresponding one of the rotationtransmission plates 14. The second coupling pins 15 are rotatablycoupled to a second rotation transmission plate 16.

Meanwhile, the central part of a driving gear 18 is rigidly coupled tothe rotation shaft of a revolving motor 17 and the driving gear 18 isengaged with a driven gear 19. The driven gear 19 is rigidly coupled tothe lower periphery of a revolution transmission shaft 20, the upperperiphery of which is engaged with the bearing tube 22 of an apparatusmain body 21. A rotation shaft 23 is rotatably fitted in a position aprescribed distance deviated from the center of the revolutiontransmission shaft 20, and the lower end of the rotation shaft 23 isrigidly coupled to the rotation center of the second rotationtransmission plate 16.

The rotation shaft 23 has its upper end coupled to a support member inthe form of a surface plate 25 through a coupling member 24. At theupper surface of the surface plate 25, a lapping machine 27 is provided.The lapping machine 27 is provided with a polishing or lapping member 28such as a lapping sheet including a medium such as electroformingdiamond through a detachably fitted surface boss 26.

On the surface plate 25, there is a tubular member 29 whose one end faceis abutted against the surface of the surface plate 25 as the movementof the tubular member in the radial and circumferential directions isrestricted.

More specifically, as shown in FIGS. 5A and 5B, the tubular member 29 isin a tubular shape whose inner diameter is larger than an outer diameterof a polishing fixture 40 which excludes a guide member 48 that will bedescribed below. The end face of the tubular member abutted against thesurface of the surface plate 25 is provided with at least three raisedportions 30 at equal intervals projecting toward the surface plate 25.The raised portions 30 fit with recessed portions 31 provided at thesurface plate 25 corresponding to the raised portions 30, so that themovement of the tubular member in the radial and circumferentialdirections is restricted. Note that FIG. 5A is a perspective view of thesurface plate 25, the tubular member 29 and the lapping machine 27, andFIG. 5B is a plan view of the tubular member 29.

The tubular member 29 as described above is formed to have a prescribedheight from the surface plate 25, so that the member must be positionedin the circumferential direction on the surface plate 25. Therefore,according to the embodiment, an additional raised portion 30 is providedbetween the three raised portions 30 to restrict the radial andcircumferential movement, so that the tubular member 29 is sure to beattached in the same direction. This allows the height of the tubularmember 29 to be highly precise accordingly.

The number and shape of the raised portions 30 and the recessed portions31 provided at the tubular member 29 and the surface plate 25 are notparticularly limited. The intervals among the three raised portions 30may be unequal and the attaching direction may always be the same, orfour or more raised portions 30 may be provided.

The tubular member 29 is placed as it is in close contact onto thesurface plate 25. The close contacted state is provided by magneticforce. More specifically, as shown in FIGS. 5A and 5B, a plurality ofpermanent magnets 29 a are embedded in the surface of the tubular member29 in abutment against the surface plate 25.

As shown in FIG. 4, the position to place the lapping machine 27 at thesurface plate 25 and the position to place the tubular member 29 arelevel with each other. The height control is highly precisely performedby grinding and the heights of the tubular member 29 and the lappingmachine 27 are also highly precisely controlled by grinding.

More specifically, the end face of the tubular member 29 on the side ofthe polishing fixture 40 and the polishing surface of the lappingmachine 27 have their heights controlled, so that no error is causedbecause of height difference among positions.

The tubular member 29 slides in contact with a guide members 48 providedat the polishing fixture 40 which will be described, and therefore ispreferably made of an oil less metal for example which has lowfrictional resistance when it slides in contact.

The tubular member 29 is ground as it is placed on the surface plate 25so that the attaching direction is always the same, and therefore itsheight from the surface plate 25 can be set highly precisely.Preferably, in a similar manner, a plurality of such tubular members 29having different heights are prepared. Thus, the height to be achievedby polishing can readily be changed with high precision.

Meanwhile, the polishing fixture 40 having a plurality of rod-shapedmembers W secured is supported by the apparatus main body 21 by asupporting mechanism 50.

The supporting mechanism 50 and the polishing fixture 40 will now bedetailed.

As shown in FIGS. 2 to 4, the polishing fixture 40 comprises apolygonal-shaped body 40A having opposite and generally parallel mainsurfaces 40B, 40C and peripheral side surfaces 40D, and a fitting 42facing a recessed portion 41 formed at each side surface 40D of the body40A. The rod-shaped member W is held between the recessed portion 41 andthe fitting 42 and the fitting 42 is secured with fitting securingscrews 43, so that the rod-shaped member W is detachably secured to thepolishing fixture 40.

According to the embodiment, the body 40A of the polishing fixture 40has a dodecagon shape, to each side of which a rod-shaped member W canbe secured, in other words, twelve rod-shaped members W altogether canbe secured. The type of the rod-shaped member W is not limited and maybe a rod-shaped member such as a ferrule, a rod-shaped member having arectangular section such as a multi-fiber ferrule and a multi-fiberoptical connector. The fitting 42 and the fitting securing screw 43 usedto secure the rod-shaped member W to the polishing fixture 40 are notparticularly limited.

In the center of the upper surface of the polishing fixture 40, apolishing fixture boss 44 is secured by boss securing screws 45. Thereis a rectangular slit 46 penetrating through the center of the polishingfixture boss 44 in the thickness-wise direction and opened at a side.There is also a plate shaped, chamfered plastic cover 47 on thepolishing fixture boss 44.

At the upper surface of the polishing fixture 40, there are therod-shaped guide members 48 that project radially outwardly from thepolishing fixture 40.

The guide members 48 are each secured to the upper surface of thepolishing fixture 40 by two guide member securing screws 49 and slide incontact with the end face of the tubular member 29 that rotates as thesurface plate 25 rotates, so that the movement of the polishing fixture40 in the pressing direction is restricted to keep the polishing fixture40 parallel relative to the surface plate 25 and the lapping machine 27during a polishing operation.

Therefore, at least three guide members 48 are necessary for thepolishing fixture 40. Meanwhile, if the number of the guide members 48is three, the rod-shaped members W could be ground more than necessarybecause part of the polishing fixture 40 might have a height lower thanthe tubular member 29 between two slidably contacting guide members 48when the polishing fixture 40 slides in contact with the tubular member29 in an oblique direction. Therefore, the number of guide members 48 ispreferably at least six. If there are many guide members 48, the weightof the polishing fixture 40 increases, which could lower the polishingprecision, so that six guide members 48 are preferably provided. Thereis a recess in the lower part in the center of the length of the guidemember 48 over the fitting 42 so that the rod-shaped member W canreadily be mounted.

According to the embodiment, as shown in FIG. 6A, the rod-shaped memberW secured to the polishing fixture 40 is a ferrule 60 including aferrule tubular body 61 made of zirconia for holding optical fibersinserted therein and a collar member or portion 62 made of a metal fitinto the rear end of the tubular body for holding inserted coatedoptical fibers. Alternatively, as shown in FIG. 6B, the rod-shapedmember W may be a ferrule 60 including the ferrule tubular body 61 andthe collar portion 62 formed in an integral form. Note that FIGS. 6A and6B are plan views each showing an example of the rod-shaped member.

According to the embodiment, the tip end face of the collar portion 62of the ferrule 60 as the rod-shaped member W is secured in abutmentagainst the polishing fixture 40. Therefore, the guide members 48slidably contact the tubular member 29 in the level as high as that ofthe tip face of the collar portion 62 of the ferrule 60, so that thelength of the ferrule tubular body 61 can readily be controlled.

FIG. 7 is a sectional view showing how the ferrule 60 having the collarportion 62 is attached to the polishing fixture 40. The polishingfixture 40 has a side face inclined outwardly downwardly in the outerperipheral direction. A contacting point P between the collar portion 62of the rod-shaped member W and the outer periphery of the ferrule 60 islocated at the upper surface of the polishing fixture 40, so that theattaching position in the height-wise direction of the rod-shaped memberW can therefore be always constant. There are guide members 48projecting radially outwardly at the upper part of the polishing fixture40. The bottom of the guide members 48 is level with the point P. Here,the rod-shaped member W is secured with the fitting 42 as if theattachment manner example shown in FIG. 4 is inclined. Thus, thedifference between the heights of the tubular member 29 and the lappingmachine 27 in FIG. 4 allows the polishing height for the rod-shapedmember W to be constant.

Meanwhile, the supporting mechanism 50 is held such that the supportingportion 51 provided approximately parallel to the lapping machine 27 atthe main body 21 is urged downward by prescribed pressing force.

More specifically, at the base end of the supporting portion 51, thereis a through hole 52 penetrating in the thickness-wise direction, and anadjusting screw 53 threadably engages with the apparatus main body 21through the through hole 52. The adjusting screw 53 is placed through anurging spring 54 that abuts against the flange portion 53 a of theadjusting screw 53 and the supporting portion 51 to urge the supportingportion 51 downward by prescribed pressing force.

The pressing force by the urging spring 54 can be adjusted based on theposition of the flange portion 53 a of the adjusting screw 53, in otherwords, based on how much the adjusting screw 53 is engaged.

Note that the supporting portion 51 has its base end portion penetratedthrough a slide pin 56 provided at the apparatus main body 21, so thatthe movement of the adjusting screw 53 in the rotation direction can berestricted.

At the tip end of the supporting portion 51, there is a pressing portion55 having a square pole shape that projects toward the polishing fixture40 and fits into the slit 46 of the polishing fixture boss 44. Thepressing portion 55 is engaged with the slit 46 of the polishing fixtureboss 44, so that the polishing fixture 40 is pressed downward to thesupporting portion 51 by prescribed pressing force and has its movementrestricted in the rotation direction.

More specifically, the polishing fixture 40 is urged toward the lappingmachine 27 by the supporting portion 51 as it has its movementrestricted in the rotation direction by the pressing portion 55 of thesupporting portion 51, and supported on the lapping machine 27 throughthe tip end of the rod-shaped members W secured by the fittings 42. Oncethe rod-shaped members W are polished for a prescribed amount, the guidemembers 48 slide in contact with the tubular member 29 on the surfaceplate 25, and support the polishing fixture 40 parallel to the lappingmachine 27, so that the amount of polishing the rod-shaped members W isrestricted.

Thus, the polishing fixture 40 is provided with the guide members 48 andthe tubular member 29 capable of supporting the polishing fixture 40through the guide members 48 is provided on the surface plate 25, sothat the lengths of the rod-shaped members W can be equal, anddeviations and variations in the radius of curvature, the polishingangle, and the eccentricity can be reduced. As in the embodiment, whenthe rod-shaped member W is a ferrule, the removal of adhesive coming outfrom the tip end of the ferrule is not necessary for equalizing thelengths of the rod-shaped members W, and therefore the polishing stepcan be simplified.

In addition, the heights of the surfaces of the tubular member 29 andthe lapping machine 27 provided at the surface plate 25 are controlled,so that the length of the rod-shaped member W can readily be specifiedand errors in the length can be prevented.

The tubular members 29 having different heights are prepared andswitchably used, so that the length of the rod-shaped member W afterpolishing can readily be controlled.

The operation of the above end face polishing apparatus according to theembodiment will now be described.

As shown in FIG. 1, the revolution motor 17 is driven to rotate therevolution transmission shaft 20 through the gears 18 and 19, and thelapping machine 27 revolves by a prescribed amount of eccentricity. Inthis case, the rotation shaft 23 is located in the revolutiontransmission shaft 20, while a plurality of rotation transmission plates14 are provided in the space between the rotation shaft 23 and the firstrotation transmission plate 12, the rotation transmission plates 14rotate around the first coupling pins 13 in the same rotation phase asthe revolution transmission shaft 20. Therefore, regardless of whetherthe first rotation transmission plate 12 is stationary or rotates, therotation of the revolution transmission shaft 20 is not restricted.

Meanwhile, the rotation motor 11 is driven to rotate the first rotationtransmission plate 12, while the first coupling pins 13 are locatedconcentrically with the first rotation transmission plate 12, andtherefore move in the same trajectory as the above. The rotation shaft23 is deviated by a prescribed distance from the center, while the shaftis coupled through the rotation transmission plates 14, and thereforethe rotation at the same number of revolutions as that of the firstrotation transmission plate 12 is transmitted to the rotation shaft 23.

Thus, the surface plate 25 revolves as it rotates by the rotation of therevolution transmission shaft 20 and the rotation shaft 23, so that thelapping machine 27 and the tubular member 29 on the surface plate 25 arerotated.

Meanwhile, with respect to the lapping member 28 at the lapping machine27, the polishing fixture 40 has its movement in the rotation directionrestricted by the pressing portion 55 of the supporting portion 51, andis urged toward the lapping machine 27. In this way, the end faces ofrod-shaped members W are pressed against the lapping member 28.

At the time, the difference between the lengths of the rod-shapedmembers W causes the polishing fixture 40 to be not parallel to thelapping machine 27, and the end faces of the rod-shaped members W arepolished into an inclined surface. However, as the polishing proceeds,the guide members 48 provided at the polishing fixture 40 slide incontact with the tubular member 29 provided on the surface plate 25, sothat the polishing fixture 40 is supported parallel to the lappingmachine 27. Therefore, the tip ends of the rod-shaped members W can bepolished with reference to the lapping machine 27. Thus, the lengths ofthe rod-shaped members W can be equalized, and deviations and variationsin the radius of curvature, the polishing angle, and the eccentricitycan be reduced. Consequently, the tip ends of the rod-shaped members Wcan be processed into an ideal convex sphere.

As in the foregoing detailed description of the embodiment, by the endface polishing apparatus according to the present invention, a pluralityof rod-shaped guide members are provided at the polishing fixture andthe polishing fixture is provided with a tubular member capable ofsupporting the polishing fixture through the guide members on thesurface plate. In this way, the polishing can be performed withreference to the lapping machine, and the lengths of the rod-shapedmembers can be equalized, and deviations and variations in the radius ofcurvature, the polishing angle and the eccentricity can be reduced. Theremoval of adhesive attached to the rod-shaped members is not necessaryfor equalizing their lengths, and therefore the polishing step can besimplified.

1. A polishing fixture comprising: at least one ferrule comprised of a tubular body supporting an optical fiber and a collar member mounted on an outer peripheral surface of the tubular body; a body having first and second opposite and generally parallel main surfaces and a peripheral side surface supporting the ferrule so that an end surface of the ferrule confronts a polishing member during a polishing operation while a longitudinal axis of the ferrule is disposed at an angle of inclination relative to the polishing member; and a guide member mounted on the first main surface of the body for maintaining the body generally parallel to the polishing member during a polishing operation.
 2. A polishing fixture according to claim 1; wherein the body supports the ferrule so that the end surface of the ferrule is disposed at the second main surface of the body and a lower portion of the collar member is disposed at the first main surface of the body.
 3. A polishing fixture according to claim 2; wherein the guide member projects radially outward from the first main surface of the body.
 4. A polishing fixture according to claim 3; wherein the guide member has an upper surface and a lower surface disposed opposite to the upper surface and connected to the first main surface of the body so that a portion of the lower surface projects radially outward from and forms an extension of the first main surface of the body.
 5. A polishing fixture according to claim 1; wherein the guide member projects radially outward from the first main surface of the body.
 6. A polishing fixture according to claim 5; wherein the guide member has an upper surface and a lower surface disposed opposite to the upper surface and connected to the first main surface of the body so that a portion of the lower surface projects radially outward from and forms an extension of the first main surface of the body.
 7. A polishing fixture according to claim 1; wherein the collar member is disposed between opposite ends of the ferrule.
 8. A polishing fixture according to claim 7; wherein the collar member contacts the outer peripheral surface of the ferrule at a contact point disposed on a line extending along the first main surface of the body.
 9. A polishing fixture according to claim 8; wherein the guide member has an upper surface and a lower surface disposed opposite to the upper surface; and wherein the contact point between the collar member and the ferrule is disposed on a line extending along the lower surface of the guide member.
 10. A polishing fixture according to claim 1; wherein the collar member is mounted on an end of the ferrule opposite an end thereof having the end surface.
 11. A polishing fixture according to claim 10; wherein the collar member contacts the outer peripheral surface of the ferrule at a contact point disposed on a line extending along the first main surface of the body.
 12. A polishing fixture according to claim 11; wherein the guide member has an upper surface and a lower surface disposed opposite to the upper surface; and wherein the contact point between the collar member and the ferrule is disposed on a line extending along the lower surface of the guide member.
 13. A polishing fixture according to claim 1; wherein the collar member contacts the outer peripheral surface of the ferrule at a contact point disposed on a line extending along the first main surface of the body.
 14. A polishing fixture according to claim 13; wherein the guide member has an upper surface and a lower surface disposed opposite to the upper surface; and wherein the contact point between the collar member and the ferrule is disposed on a line extending along the lower surface of the guide member.
 15. In combination: a plurality of ferrules each comprised of a tubular body supporting an optical fiber and a collar member mounted on an outer peripheral surface of the tubular body; a body having first and second opposite and generally parallel main surfaces and a plurality of peripheral side surfaces for supporting the respective ferrules so that end surfaces of the ferrules confront a polishing member during a polishing operation while a longitudinal axis of each of the ferrules is disposed at an angle of inclination relative to the polishing member; and a plurality of guide members mounted on the first main surface of the body for maintaining the body generally parallel to the polishing member during a polishing operation.
 16. A polishing fixture according to claim 15; wherein the plurality of ferrules comprises at least three ferrules.
 17. A polishing fixture according to claim 16; wherein the plurality of guide members comprises at least six guide members projecting radially outward from the first main surface of the body.
 18. A polishing fixture according to claim 15; further comprising a plurality of fitting members for connecting the respective ferrules to the respective peripheral side surfaces of the body.
 19. A polishing fixture according to claim 15; wherein the guide members project radially outward from the first main surface of the body.
 20. In combination: a support member having a main surface and mounted for undergoing rotational movement; a tubular member mounted on the support member for rotation therewith; a polishing member mounted on the support member for rotation therewith during a polishing operation; a plurality of ferrules each having a tubular body supporting an optical fiber and a collar member mounted on an outer peripheral surface of the tubular body; a polishing fixture comprised of a body having first and second opposite and generally parallel main surfaces and a plurality of peripheral side surfaces for supporting respective ferrules so that end surfaces of the ferrules confront the polishing member during a polishing operation while a longitudinal axis of each of the ferrules is disposed at an angle of inclination relative to the polishing member; and a plurality of guide members mounted on the first main surface of the body of the polishing fixture for contacting the tubular member during a polishing operation to maintain the body of the polishing fixture generally parallel to the support member.
 21. A combination according to claim 20; wherein for each of the ferrules, the collar member contacts the outer peripheral surface of the ferrule at a contact point disposed on a line extending along the first main surface of the body of the polishing fixture.
 22. A combination according to claim 20; further comprising a plurality of fitting members for connecting the respective ferrules to the respective peripheral side surfaces of the body of the polishing fixture. 